Two trains leave the station at the same time, one heading east and the other west. the eastbound train travels at 80 miles per hour. the westbound train travels at 90 miles per hour. how long will it take for the two trains to be 306 miles apart?

How does the amount of energy required to hold each proton and neutron in the nucleus compare to the energy released when they are removed?

This is important 1. what happens to the speed of molecules in water vapor when it condenses to form a liquid? (2 points) the molecules slow down. the molecules speed up. the molecules slow down and then speed up. the molecules speed up and then slow down. 2. how might human activities change to compensate for a decrease in water supplies? (2 points) humans might build a factory. humans might build drainage systems. humans might extract more water from the ground. human behavior does not change because of the water cycle. i'll be grateful if anyone can answer these 2 questions !

What is the single most important equation in all of physics?